Add presence module V2 (#2312)

* Syncapi presence

* Clientapi http presence handler

* Why is this here?

* Missing files

* FederationAPI presence implementation

* Add new presence stream

* Pinecone update

* Pinecone update

* Add passing tests

* Make linter happy

* Add presence producer

* Add presence config option

* Set user to unavailable after x minutes

* Only set currently_active if online
Avoid unneeded presence updates when syncing

* Tweaks

* Query devices for last_active_ts
Fixes & tweaks

* Export SharedUsers/SharedUsers

* Presence stream in MemoryStorage

* Remove status_msg_nil

* Fix sytest crashes

* Make presence types const and use stringer for it

* Change options to allow inbound/outbound presence

* Fix option & typo

* Update configs

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

syncapi/producers/federationapi_presence.go

@@ -0,0 +1,48 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package producers
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/nats-io/nats.go"
+)
+
+// FederationAPIPresenceProducer produces events for the federation API server to consume
+type FederationAPIPresenceProducer struct {
+	Topic     string
+	JetStream nats.JetStreamContext
+}
+
+func (f *FederationAPIPresenceProducer) SendPresence(
+	userID string, presence types.Presence, statusMsg *string,
+) error {
+	msg := nats.NewMsg(f.Topic)
+	msg.Header.Set(jetstream.UserID, userID)
+	msg.Header.Set("presence", presence.String())
+	msg.Header.Set("from_sync", "true") // only update last_active_ts and presence
+	msg.Header.Set("last_active_ts", strconv.Itoa(int(gomatrixserverlib.AsTimestamp(time.Now()))))
+
+	if statusMsg != nil {
+		msg.Header.Set("status_msg", *statusMsg)
+	}
+
+	_, err := f.JetStream.PublishMsg(msg)
+	return err
+}